This room is an example of good residential acoustics. There are several principles at work here:
1. Diffusion, the rough surface of the masonry fireplace will scatter incoming soundwaves without causing echoes or reverb which is usually perceived as unpleasant. Also the many surfaces of the exposed roof trusses will have a similar effect.
2. Non-parallel surfaces, the exposed roof deck
undersides are not parallel or at right angles to the walls or the floor. That prevents echoes or unpleasant emphasis at certain frequencies.
3. Absorption, the rugs, furniture and window shades will absorb high frequency noise and reduce what is perceived as "noisiness".